Long-term objectives. Since there is biological evidence that exposure to electromagnetic fields (EMFs) may be related to some health effects at the cellular level, it is important to determine the current densities and EMFs induced in the human body in meaningful exposure situations. The objective is to develop a new tool for determining and understanding the currents and fields induced in biologically important organs on the macroscopic and cellular levels. This involves their dependence on the frequency, magnitude and direction of the incident electromagnetic field. Specific Aims of the research are: a. The identification of exposure situations that permit the analytical determination of the electromagnetic field in which a body is immersed. b. The derivation of accurate formulas that resists the incident EMFs to the currents and fields induced in the exposed body and clearly display their dependence on the frequency, dimensions of the body, and magnitude and direction of the external field. c. The determination of the current density and in important organs of the body, the associated local field and its action at the cellular level. Research design and methods. a. Apply known accurate formulas for the complete EMF of horizontal and vertical electric dipoles to determine the EMFs generated by power lines, VLF transmitters, shipboard antennas, and determine the average fields and currents in the body for the various configurations. For example, at low frequencies (50 Hz to 10 MHz), the body behaves like an electrically and the axial (circulating) current is due primarily to the electric (magnetic) field. c. Selected cross sections of the body containing biologically important organs act as conductances in parallel carrying a known axial current. With the known conductivities and dimensions of the organs, determine the current density and electric field in each organ. d. Study the effects of these at the cellular level and relate to in vitro measurements.